Bulk material can exhibit varying flow characteristics based on differences in the characteristics of the particles that comprise the bulk material. Examples of characteristics of particles that may affect flow are size, shape, texture, and density. External factors such as humidity, precipitation (if materials are stored outside), and temperature can further influence the characteristics of the particles and their resulting flow ability. Settling of bulk material in storage will also impact the flow characteristics. Flow ability issues that result from particle differences comprise nesting, caking, and bridging. Transportation of the material can further exacerbate these flow ability issues by causing additional settling and nesting due to vibration of the material caused by movement. Bridging, enhanced by the nesting of the material, typically is exhibited when the bulk material is exiting a container. This nesting and resulting bridging effect may be due to the composition, texture, or density of the bulk material in addition to restriction points of the container being unloaded. The nesting and resulting bridging inhibits the flow ability of the bulk material.
Bulk material can be moved to a location of use or storage in a transport container such as a tractor-trailer. When the transport container arrives at the location, the bulk material is unloaded from the transport container for storage or processing. Existing transport containers and unloading systems each have independent issues with handling bulk materials. For example, gravity drop trailers can experience hopper plugging during unloading due to the bridging effects over a small opening. Trailers with conveyor floors, in addition to bridging issues that may occur over the conveyor, have mechanically complex components which can increase purchase costs and maintenance costs. Trailers with walking-beam floors have moving parts and can have more components which can make trailers with walking-beam floors subject to increased equipment failures as compared to other trailers. Side-dump trailers with slightly annular cross-sectional shape limit the hauling capacity of side-dump trailers as compared to box style trailers. Box style side-dump trailers in which the entire box is tilted to facilitate unloading the material have moving parts and can have more components which can make these trailers subject to increased equipment failures.
Biomass is an example of bulk material. Biomass comprises plant matter that can be suitable for direct use as a fuel/energy source or as a feedstock for processing into another bioproduct (e.g. a biofuel such as cellulosic ethanol) produced at a biorefinery (such as an ethanol plant). Biomass may comprise, for example, corncobs and stover (e.g. stalks and leaves) made available during or after harvesting of the corn kernels. In order to be used or processed, biomass will be harvested and collected from the field and transported to the location where it is to be used or processed. Biomass (such as corncobs and stover) may be collected and stored in piles at the edge of the field. The piles of biomass are then collected and transported from the field to the location of intended use or processing.
It would be advantageous to provide for an apparatus for unloading bulk material. It would also be advantageous to provide for an apparatus for unloading bulk material from a transport container. It would also be advantageous to provide for high volume unloading of bulk material that can mitigate plugging of the bulk material within the transport container while facilitating flow of the bulk material out of the transport container. It would be further advantageous to provide for an apparatus for unloading bulk material that has few components and few moving parts.